Beam failure detection

Abstract

Embodiments are presented herein of apparatuses, systems, and methods for a user equipment device (UE) to perform beam failure detection. The UE may establish communication with a base station. The UE may determine one or more beams to perform downlink communication from the base station. The UE may receive, from the base station, an indication of a first type of downlink reference signals to perform beam failure detection. The UE may perform signal quality measurements for the one or more beams using the first type of downlink reference signals. The UE may determine beam failure of at least one beam of the one or more beams based on said performing signal quality measurements.

What is claimed is: 
     
         1 . A processor, comprising:
 memory storing instructions that, when executed, cause the processor to:
 determine one or more beams to perform downlink communication from a base station; 
 receive, from the base station, a transmission configuration indicator (TCI) in an implicit indication, the TCI indicating:
 a sounding reference signal (SRS), and 
 a first type of downlink reference signals based on the TCI; 
 
 determine that the first type of downlink reference signals are used in a same bandwidth part (BWP) as a control resource set (CORESET); 
 select the first type of downlink reference signals in order to perform beam failure detection and based at least in part on:
 a lowest resource identifier (ID) of the first type of downlink reference signals; 
 the implicit indication; 
 a pathloss estimation for the SRS; 
 the determination that the first type of downlink reference signals are used in the same BWP as the CORESET; and 
 the SRS and the first type of downlink reference signals being indicated in the TCI; 
 
 perform signal quality measurements for the one or more beams using the first type of downlink reference signals; and 
 determine beam failure of at least one beam of the one or more beams based on said performing signal quality measurements. 
   
     
     
         2 . The processor of  claim 1 , wherein said determining beam failure is performed by comparing the signal quality measurements to a threshold. 
     
     
         3 . The processor of  claim 1 , wherein said determining beam failure comprises, for n consecutive times:
 performing a respective signal quality measurement for a first beam; and   comparing the respective signal quality measurement to a signal quality threshold;   wherein beam failure is determined when the respective signal quality measurement falls below a signal quality threshold n consecutive times.   
     
     
         4 . The processor of  claim 1 , wherein the first type of downlink reference signals comprise synchronization signal block (SSB) or channel state information reference signal (CSI-RS). 
     
     
         5 . The processor of  claim 1 , wherein the TCI is associated with a control resource set (CORESET), wherein the TCI indicates a plurality of types of downlink reference signals, wherein said selecting the type of downlink reference signals comprises selecting the first type of downlink reference signals from the plurality of types of downlink reference signals indicated in the TCI. 
     
     
         6 . A method, comprising:
 determining one or more beams to perform downlink communication from a base station;   receiving, from the base station, a transmission configuration indicator (TCI) in an implicit indication, the TCI indicating:
 a sounding reference signal (SRS), and 
 a first type of downlink reference signals based on the TCI; 
   determining that the first type of downlink reference signals are used in a same bandwidth part (BWP) as a control resource set (CORESET);   selecting the first type of downlink reference signals in order to perform beam failure detection and based at least in part on:
 a lowest resource identifier (ID) of the first type of downlink reference signals; 
 the implicit indication; 
 a pathloss estimation for the SRS; 
 the determination that the first type of downlink reference signals are used in the same BWP as the CORESET; and 
 the SRS and the first type of downlink reference signals being indicated in the TCI; 
   determining based at least in part on the SRS being indicated in the TCI, the first type of downlink reference signals for performing beam failure detection;   performing signal quality measurements for the one or more beams using the first type of downlink reference signals; and   determining beam failure of at least one beam of the one or more beams based on said performing signal quality measurements.   
     
     
         7 . The method of  claim 6 , wherein the TCI is associated with a control resource set (CORESET), wherein the TCI indicates a plurality downlink reference signals, wherein said selecting the downlink reference signals comprises selecting the first type of downlink reference signals from the plurality downlink reference signals indicated in the TCI. 
     
     
         8 . The method of  claim 6 , wherein said determining beam failure comprises, for n consecutive times:
 performing a respective signal quality measurement for a first beam; and   comparing the respective signal quality measurement to a signal quality threshold;   
       wherein beam failure is determined when the respective signal quality measurement falls below a signal quality threshold n consecutive times. 
     
     
         9 . The method of  claim 6 , wherein the first type of downlink reference signals comprise synchronization signal block (SSB) or channel state information reference signal (CSI-RS). 
     
     
         10 . A non-transitory computer readable storage medium storing program instructions executable by one or more processors, which when executed, cause the one or more processors to:
 determining one or more beams to perform communication with a base station;   receive, from the base station, a transmission configuration indicator (TCI) in an implicit indication, the TCI indicating:
 a sounding reference signal (SRS), and 
 a first type of downlink reference signals based on the TCI; 
   determine that the first type of downlink reference signals are used in a same bandwidth part (BWP) as a control resource set (CORESET);   select the first type of downlink reference signals in order to perform beam failure detection and based at least in part on:
 a lowest resource identifier (ID) of the first type of downlink reference signals; 
 the implicit indication; 
 a pathloss estimation for the SRS; 
 the determination that the first type of downlink reference signals are used in the same BWP as the CORESET; and 
 the SRS and the first type of downlink reference signals being indicated in the TCI; 
   perform signal quality measurements for the one or more beams using the first type of downlink reference signals; and   determine beam failure of at least one beam of the one or more beams based on said performing signal quality measurements.   
     
     
         11 . The non-transitory computer readable storage medium of  claim 10 , wherein the TCI is associated with a control resource set (CORESET), wherein the TCI indicates a plurality of types of downlink reference signals, wherein said selecting the type of downlink reference signals comprises selecting QCL-TypeD downlink reference signals from the plurality of types of downlink reference signals indicated in the TCI. 
     
     
         12 . The non-transitory computer readable storage medium of  claim 10 , wherein selecting the first type of downlink reference signals is based on the implicit indication and comprises selecting the first type of downlink reference signals used for initial access. 
     
     
         13 . The non-transitory computer readable storage medium of  claim 10 , wherein said determining beam failure comprises comparing a plurality of signal quality measurements to a threshold. 
     
     
         14 . The non-transitory computer readable storage medium of  claim 10 , wherein the first type of downlink reference signals comprise synchronization signal block (SSB) or channel state information reference signal (CSI-RS). 
     
     
         15 . The non-transitory computer readable storage medium of  claim 10 , wherein said determining beam failure comprises, for n consecutive times:
 performing a respective signal quality measurement for a first beam; and   comparing the respective signal quality measurement to a signal quality threshold;   wherein beam failure is determined when the respective signal quality measurement falls below a signal quality threshold n consecutive times.   
     
     
         16 . The non-transitory computer readable storage medium of  claim 10 , wherein said performing signal quality measurements comprises measuring at least one of:
 a block error rate (BLER);   a signal to interference plus noise ratio (SINR);   a signal to noise ratio (SNR);   a received signal strength indicator (RSSI);   a reference signal received power (RSRP); or   a reference signal received quality (RSRQ).   
     
     
         17 . The non-transitory computer readable storage medium of  claim 10 , wherein the TCI is associated with a control resource set (CORESET), wherein the TCI indicates a plurality of types of downlink reference signals, wherein said selecting the type of downlink reference signals comprises selecting the first type of downlink reference signals from the plurality of types of downlink reference signals indicated in the TCI. 
     
     
         18 . The non-transitory computer readable storage medium of  claim 10 , wherein at least one of the one or more processors is a baseband processor.